vfs: add vfs_select_inode() helper

[karo-tx-linux.git] / include / linux / dcache.h

diff --git a/include/linux/dcache.h b/include/linux/dcache.h
index d67ae119cf4eb9d3143d5019108f1d7fbf252b88..d81746d3b2da18477dd7b7db6b0c37b2123c817a 100644 (file)
--- a/include/linux/dcache.h
+++ b/include/linux/dcache.h
@@ -161,6 +161,7 @@ struct dentry_operations {
        struct vfsmount *(*d_automount)(struct path *);
        int (*d_manage)(struct dentry *, bool);
        struct inode *(*d_select_inode)(struct dentry *, unsigned);
+       struct dentry *(*d_real)(struct dentry *, struct inode *);
 } ____cacheline_aligned;
 
 /*
@@ -227,6 +228,7 @@ struct dentry_operations {
 #define DCACHE_MAY_FREE                        0x00800000
 #define DCACHE_FALLTHRU                        0x01000000 /* Fall through to lower layer */
 #define DCACHE_OP_SELECT_INODE         0x02000000 /* Unioned entry: dcache op selects inode */
+#define DCACHE_OP_REAL                 0x08000000
 
 extern seqlock_t rename_lock;
 
@@ -409,9 +411,7 @@ static inline bool d_mountpoint(const struct dentry *dentry)
  */
 static inline unsigned __d_entry_type(const struct dentry *dentry)
 {
-       unsigned type = READ_ONCE(dentry->d_flags);
-       smp_rmb();
-       return type & DCACHE_ENTRY_TYPE;
+       return dentry->d_flags & DCACHE_ENTRY_TYPE;
 }
 
 static inline bool d_is_miss(const struct dentry *dentry)
@@ -584,4 +584,24 @@ static inline struct dentry *d_backing_dentry(struct dentry *upper)
        return upper;
 }
 
+static inline struct dentry *d_real(struct dentry *dentry)
+{
+       if (unlikely(dentry->d_flags & DCACHE_OP_REAL))
+               return dentry->d_op->d_real(dentry, NULL);
+       else
+               return dentry;
+}
+
+static inline struct inode *vfs_select_inode(struct dentry *dentry,
+                                            unsigned open_flags)
+{
+       struct inode *inode = d_inode(dentry);
+
+       if (inode && unlikely(dentry->d_flags & DCACHE_OP_SELECT_INODE))
+               inode = dentry->d_op->d_select_inode(dentry, open_flags);
+
+       return inode;
+}
+
+
 #endif /* __LINUX_DCACHE_H */